title: Highly-porous metal option for primary cementless acetabular fixation. What is the evidence?
abstract: The purported improvement in the initial stability and enhanced osseointegration has stimulated a recent increase in the use of highly-porous interfaces for acetabular fixation in cementless hip arthroplasty. The aim of this study was to comprehensively review the literature and report the clinical outcomes of highly-porous metals in primary cementless acetabular fixation. Aseptic survivorship, osteolysis, Harris hip scores, cup migration and the incidence of peri-acetabular gaps, and peri-prosthetic fractures were assessed. A search of four electronic databases yielded 16 level IV studies that reported on the use of these newer highly-porous metals in primary cementless acetabular fixation. The mean cup-survivorship for aseptic loosening with the use of these modern interfaces was 100% and the mean acetabular component revision rate for any reason at 100-component years was 0.14 (range 0 to 0.55) at a mean follow-up of five years. The functional outcomes were also noted to be excellent with significant improvement in Harris Hip scores from a mean of 46 points pre-operatively (15 to 85 points) to 91 points (range, 80 to 97 points) post-operatively. Cup-stability was found to be excellent with a mean incidence of migration of less than 2% at mean follow-up of five years (range, 0.6 to 12 years). None of the studies on primary arthroplasty had any evidence of progressive peri-acetabular osteolysis in their study population at final follow-up. In summary, randomised controlled trials and long-term evaluation of these highly-porous implants will be needed in future to determine their potential superiority and to justify the increased cost.
authors.affiliation: Center for Joint Preservation and Replacement, Rubin Institute for Advanced Orthopaedics, Sinai Hospital of Baltimore, Baltimore, Maryland - USA.
authors.forename: Samik
authors.initials: S
authors.lastname: Banerjee
authors.forename: Kimona
authors.initials: K
authors.lastname: Issa
authors.forename: Bhaveen H
authors.initials: BH
authors.lastname: Kapadia
authors.forename: Robert
authors.initials: R
authors.lastname: Pivec
authors.forename: Harpal S
authors.initials: HS
authors.lastname: Khanuja
authors.forename: Michael A
authors.initials: MA
authors.lastname: Mont
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing / Q000379:methods; D016062:Porosity; D011474:Prosthesis Design; D016896:Treatment Outcome